Process for preparing m-chlorobenzene sulphonyl chloride and m-dichlorobenzene

ABSTRACT

Meta-chlorobenzene sulphonyl chloride and metadichlorobenzene are prepared by reacting benzene sulphonyl chloride with chlorine in the presence of a Friedel-Crafts catalyst at a temperature of from 20* to 180*C. After removing the catalyst, the resulting mchlorobenzene sulphonyl chloride is reacted to form mdichlorobenzene. The m-chlorobenzene sulphonyl chloride is preferably isolated prior to being reacted to m-dichlorobenzene. The reaction forming m-dichlorobenzene can be carried out via thermal clevage, thermal chlorolysis or chlorolysis initiated photochemically or by radicals.

United States Patent Blank et al.

[ July 29, 1975 PROCESS FOR PREPARING M-CHLOROBENZENE SULPHONYL CHLORIDEAND M-DICHLOROBENZENE Inventors: Heinz-Ulrich Blank,

Odenthal-Globusch; Karlfried Wededeyer, Cologne, both of Germany; JosefEbersberger, deceased. late of Bergen. Obb.. Germany, by TheaEbersberger, heiress Assignee: Bayer Aktiengesellschaft,

Leverkusen, Germany Filed: Apr. 30, 1974 Appl. No.: 465,649

Foreign Application Priority Data May 24, 1973 Germany 2326414 US. Cl.204/158 HA; 260/243 R; 260/694 Int. Cl. B0lj l/10; CO7b 9/00; C07c143/70 Field of Search ..204/158 HA: 260/543 R. 260/694 {56] ReferencesCited UNITED STATES PATENTS 3,230,268 1/1966 Kobayashi et a1 204/158 HA3,689,546 9/1 72 Kirch 260/544 D 3,844,917 10/1974 Miller 204/158 HAPrimary Examiner-Howard S. Williams Attorney, Agent,- Or FirmBurgess,Dinklage & Sprung [57] ABSTRACT Meta-chlorobenzene sulphonyl chlorideand metadichlorobenzene are prepared by reacting benzene sulphonylchloridewith chlorine in the presence of a Friedel-Crafts catalyst at atemperature of from 20 to 180C. After removing the catalyst, theresulting mchlorobenzene sulphonyl chloride is reacted to formm-dichlorobenzene'. The m-chlorobenzene sulphonyl chloride is preferablyisolated prior to being reacted to m-dichlorobenzene. The reactionforming mdichlorobenzene can be carried out via thermal clevage, thermalchlorolysis or chlorolysis initiated photochemically or by radicals.

7 Claims, No Drawings 1 PROCESS FOR PREPARING M-CHLOROBENZENE SULPHONYLCHLORIDE AND M-DIC-HLOROBENZENE BACKGROUND-Q1; 1 5

The invention relates to a process for the production of m-chlorobenzenesulphonyl chloride and mdichlorobenzene. 1

SUMMARY 7 More particularly, the invention relates to a particularlyadvantageous process for the production of mchlorobenzene sulphonylchloride and mdichlorobenzene, having the characteristic feature thatbenzene-sulphonyl chloride isreacted in the presence of Friedel-Craftscatalysts at a temperature in the range of from to 180C with chlorine,and the resulting m-chlorobenzene sulphonyl chloride, afterremoval ofthe catalyst and optionally after intermediate separa- 20 tion, isoptionally reacted in the presence of chlorinating agents to formm-dichlorobenzene.

In the first stage of the process, it is preferably to work at 10 to150C, more particularly at 20 to The invention also provides a processfor the production of m-chlorobenzene sulphonyl chloride, in whichbenzene sulphonyl chloride is reacted with chlorine in the presence of aFriedel-Crafts catalyst at a temperature of from 0 to 150C.

DESCRIPTION standards of purity are required for these startingcompounds, The, degree ofpurity of technically produced benzenesulphonyl chloride is adequate for carrying out the process.according tothe invention.

Generally speaking, in the first stage of the process, optionally afterprevious saturation of the reaction mixture. with hydrogen chloride gas,a sufficient quantity of dry chlorine is introduced until all thebenzene sulphonyl chloride is reacted. So as to avoid secondaryreactions,.it may be expedient to .chlorinate only up to a conversion offrom 10 to 95 percent (advantageously from to 90%) and once again tointroduce unreacted benzene sulphonyl chloride after isolation. In thecase of the practically complete chlorination, the introduced quantityof chlorine amounts to 1 to 5 mols, advantageously 1.0 to 2.5 mols, permol of reacted benzene sulphonyl chloride. The progress of the reactionis preferably monitored ,by weighing or gas chromatography. When workingwith an excess of chlorine, any unreacted chlorine is recovered, forexample. by condensation and is returned to the reaction or supplied toa second chlorination batch. After removing the Friedel-Crafts catalyst,the m-chlorobenzene sulphonyl chloride which has formed can be directlyreacted, optionally after intermediate isolation, to formmdichlorobenzene, for example bythe following methods: I

a. Thermal cleavage:

b. Thermal chlorolysis:

SO2C1 hlonnatlon agent i sulphuryl Liquid phase C1 or 15o 260C S0,,

Gas phase 200 lt is also possibleto work in the presence 'of those inertdiluents which are commonly used with halogenation reactions, so as, forexample, to produce a better dissipation of heat. The following arementioned as examples of diluents: carbon tetrachloride,tetrachlorethane, perchlorethylene, glacial acetic acid and petroleumether.

, radicals:

c. Chlorolysis initiated photochemically or by 'e.g'. chlorine ors'ulphuryl chloride The reaction optionally takes palce withsimultaneous 40 ultraviolet radiation.

The operation is here carried out with ultraviolet irradiation (e.g.quartz lamp). and 0.1 to 5. advantageously 1.0 to 2.0 mols ofchlorinating agent. advantageously chlorine or sulphuryl chloride, areused for each mol of m-chlorobenzene sulphonyl'chloride. The use ofradical formers, as for example azo-bis-isobutyronitrile or peroxides.such as benzoyl peroxide, in amounts of from 0.1 to percent by weight,based on mchlorobenzene sulphonyl chloride, can also be advantageous.

With the processes (a) to (c), large variations in the reactionconditions are possible. At temperatures higher than approximately 180C,the reaction can, for example, proceed simultaneously according to thevariants (a) to (c). The methods (a) to (c) are generally carried out inthe liquid phase at temperatures of from C to 300C or in the gaseousphase at temperatures of from 200 to 400C, and at pressures of from 1mm.l-lg to several atmospheres.

When working in the liquid phase in the upper temperature range. thepreferred form of reaction is thermal chlorolysis (b), using-chlorine orsulphuryl chloride in the temperature range of from 150 to 260C, moreespecially 180 to 230C, possibly under reduced or slightly raisedpressure, but advantageously under normal pressure.

The thermal cleavage (at) is preferably carried out at 200 to 260C andwith simultaneous ultraviolet irradiation. 1f the thermal cleavage (a)is carried out in the liquid phase,.then in the same way as with thethermal chlorolysis (b), the operation preferably takes place at theboiling point of the reaction mixture. The reaction temperatureaccordingly lies between approximately the boiling point of them-dichlorobenzene as lower limit and that of the m-chlorobenzenesulphonyl chloride as upper limit, and is determined by the proportionsof m-dichlorobenzene and halogenating agent in the reaction mixture. Itis optionally possible to work in the presence of halogen transferagents, for example PCl ,'PCl POCl or COCl and/or in the presence ofsolvents of high boiling point, for example hexachlorobenzene orpolychlorinated biphenylene.

In another similarly preferred form of the reaction, the chlorolysis iscarried out in the liquid phase with ultraviolet irradiation or withaddition of radical formers (c) in the temperature range of from 20 to260C, preferably from 50 to 210C and more particularly from 70 to 150C,optionally in the presence of inert diluents, for example carbontetrachloride. Unreacted initial material and unreacted or excess orreformed chlorinating agents are recovered with (a). (b) and (c) and arereintroduced into the reaction mixture.

When carrying out the reaction in the liquid phase, the progress of thereaction is preferably monitored by gas chromatography. It may beadvantageous for the formed m-dichlorobenzene to be distilled offcontinuously through a column from the reaction mixture. Depending onthe chosen reaction temperature, this takes place at a reduced orslightly raised pressure. When dis- 4 tilling off m-dichlor obenzene, itis preferred to work at normal pressure.

It is cxtremely'surprising that the process according to the inventioncan be carried out, since with the chlorination of benzene sulphonylchloride in the manner similar to the known chlorination ofp-chlorobenzene sulphonyl chloride, it wasto be expected that therewould be an exchange of the SO Cl group for chlorine and hence theformation of chlorobenzenes (.lourn. of American Chemical Soc. 72, page1215 (1950)). On the basis of the prior art and because of the knownpossibility of converting p-toluosulphonic acid chloride to4-methyl-3-chlorobenzene sulphonyl chloride,4-methyl-3,5-dichlorobenzene sulphonyl chloride and4-methyl-2,3,5-trichlorobenzene sulphonyl chloride (German Pat. Nos.133,000 and 210,856), it was to be assumed that, in the case ofchlorination of the benzene sulphonyl chloride ring, the ring must beactivated, at least by alkyl groups. It was not at all possible toforesee a smoothly proceeding and selective meta-chlorination of benzenesulphonyl chloride. Hitherto, mchlorobenzene sulphonyl chloride was onlyobtainable with moderate yields after multi-stage processes (.lourn. ofOrg. Chem. 21, page 1382 (1956); Ber. 90, 841 852 (1957); Australian.lourn. Chem. 6, pages 318 320 1953); Rect. Trav. Chim. 84, pages 24 30(1965)). The process according to the invention thus makes it possiblefor m-chlorobenzene sulphonyl chloride to be prepared in a particularlyadvantageous manner. Furthermore, m-dichlorobenzene can be produced onan industrial scale by a particularly simple procedure. The process issuitable for continuous operation, since it is possible in both stagesfor unreacted starting products and intermediate products, including thehalogenation agents, to be returned to the reaction after beingfractionated in continuously operated columns. The-overall processaccordingly proceeds in accordance with the reaction equation:

HCI 4- SO (:1 2

m-Chlorobenzene sulphonyl chloride and mdichlorobenzene are valuableintermediate products for the production of plant protection agents. m-Dichlorobenzene, can, for example, be used for the production of2,4-dichloronitrobenzene, which is used as an intermediate for theproduction of benzo(c)- cinnoline dyestuffs (Offenlegungsschrift No.2,041,689).

The invention is illustrated in the following Examples.

EXAMPLE 1 353 g (2 mols) of benzene sulphonyl chloride and 10 g of ironfilings are initially placed in a conventional chlorination apparatus.Chlorine is introduced at 50 to 52C until there is an increase in weightof 72 g. Suction-filtering is carried out. followed by washing with icedwater until neutral and drying over Na SO Approximately yield 315 g(67.35% of mchlorobenzene sulphonyl chloride, 26.85 percent based onstarting material).

Calculated yield: 66 percent of the theoretical of mchlorobenzenesulphonyl chloride. (Examples 1 to 16 illustrate the first stage of theprocess).

EXAMPLES 2 to 12 The yield of m-chlorobenzene sulphonyl chloride,established by gas'chromatography and related to reacted startingmaterial, amounts of 88 percent of the theoretical.

EXAMPLE 16 2.5 g of aluminium chloride are added to 177 g (1 mol) ofbenzene sulphonyl chloride. Saturation takes place at 75C with hydrogenchloride and chlorine is introduced until the increase in weight is g.

The yield of m-chlorobenzene sulphonyl chloride, relative to reactedstarting material, and determined by gas chromatography, amounts to 70percent of the theoretical.

EXAMPLE 17 Chlorine is introduced at 187 to 205C into 527 g (2.5 mols)ofm-chlorobenzene sulphonyl chloride and Cale. g. crude Example Solventg by wt.) Reaction g increase Cale. yield ml CCl iron filingstemperature in weight conversion product of theoretical of Cm-chlorobenzcncsulphonyl chloride 2 10 (5.65) 20 24 37 41 166.3 64 3 10(5.65) 91 96 37 71 172.4 67 4 10 (5.65) 130 136 36 64 170.0 62.4 5 10010 (5.65) 46 53 83 1890*) 77 6 0.34 (0.19) 48 55 35 76 199 81 7 0.09(0.05) 49 56 9 9 186*) 80 8 10 (5.65) 160 170 34 66 105 ll 9 10 (5.65) O29 22 173 69 ,10 Catalyst by wt.)

1.77 g Fe 0.18 g 1 49 S5 88 189 67 l l 1.77 g Fe 0.18gS 48-51 37 58 1918O 12 1.77 g FeCl 5O 52 34 89 205 77 *After removal ofCCl, UndistilledEXAMPLE 13 the resulting m-dichlorobenzene is continuously dis- 706 g (4mols) of benzene sulphonyl chloride and 10 g of iron filings areinitially placed in a two-litre stirrertype apparatus. The mixture issaturated with gaseous hydrochloric acid and chlorine is introduced atto C until there is an increase in weight of 150 g. Distillation takesplace after removal of the catalyst. 741 g of crude product of b.p.: 113to 120C/3 mm.Hg are obtained. By fine rectification, 133 g of benzenesulphonyl chloride (19% recovery) of b.p.: 89C/l.3 mm.Hg and 572 g ofm-chlorobenzene sulphonyl chloride (yield relative to reacted benzenesulphonyl chloride 83% of the theoretical) of b.p.: lO2C/l.6 to 1.7mm.Hg are obtained.

Further processing, see Examples 17 to 25.

EXAMPLE 14 250 g (1.41 mols) of benzene sulphonyl chloride arechlorinated with the addition of 7 g of antimony-(111)- chloride at 78C.After an increase in weight of 51 g, 250 ml of carbon tetrachloride areadded and extraction is carried out by shaking with cold concentratedhydrochloric acid. The substance is washed until neutral with water,dried and distilled.

Yield: 138 g (46.5 percent of the theoretical) of mchlorobenzenesulphonyl chloride.

EXAMPLE 15 2.5 g of iodine are added to 177 g (1 mol) of benzenesulphonyl chloride. Saturation with hydrogen chloride takes place at 50Cand chlorine is introduced until there is an increase in weight of 8 g.

EXAMPLE 18 424 g (2 mols) of m-chlorobenzene sulphonyl chloride and 100ml of carbon tetrachloride are irradiated at 50C with ultraviolet light(mercury immersion lamp), with simultaneous introduction of a stream ofchlorine (8.7 g per hour). After 5 3/4 hours, the reaction mixturecontains 15.5 percent of mdichlorobenzene and 81.8 percent ofm-chlorobenzene sulphonyl chloride. Yield: 86 percent ofmdichlorobenzene, based on reacted m-chlorobenzene sulphonyl chloride.

EXAMPLE 19 270 g of sulphuryl chloride are added to 424 (2 mols) ofm-chlorobenzene sulphonyl chloride in 100 ml of carbon tetrachloride; atC and under irradiation with ultraviolet light (mercury immersion lamp).The waste gas (sulphur dioxide and chlorine) escaping by way of acondenser still contains sulphuryl chloride.

After 5 /2 hours, the reaction mixture contains 31.3 percent ofm-dichlorobenzene and 67.8 percent of mchlorobenzene sulphonyl chloride.Yield of mchlorobenzene: 97 percent of the theoretical, based on reactedm-chlorobenzene sulphonyl chloride.

EXAMPLE 20 1414 g of m-chlorobenzene sulphonyl chloride are stirred withultraviolet irradiation (mercury immersion lamp) at a sump temperatureof 240 to 247C. The product. boiling at 190C, is distilled off through asilver-jacketed column (diameter 2.5 cm) with a height of 40 cm andfilled with Raschig rings X 5 mm). After a reaction time of 100 minutes,two fractions are obtainedz 61.3 g of Fraction 1 89.9% ofm-dichlorobenzene and 10.1% of chlorobenzene; and

83.1 g of Fraction 2 98.3% of m-dichlorobenzene and 1.7% ofchlorooenzene.

As well as 87.3 percent of m-chlorobenzene sulphonyl chloride, theresidue (989 g) also contains 4.7 percent of m-dichlorobenzene.

The yield of m-dichlorobenzene amounts to 48% of the theoretical.

EXAMPLE 21 211 g (1 mol) of m-chlorobenzene sulphonyl chloride areinitially provided and heated by means of an oil bath. 128.3 g (0.96mol) of sulphuryl chlorine are introduced dropwise at a reactiontemperature of from 196 to 224C for 4 /2 hours and, using a 40 cm silvercolumn (glass Raschig rings 4 X 4 mm), mdichlorobenzene is withdrawn athead temperatures of from 140 to 173C (760 mm.Hg), and at the same timesome sulphuryl chloride distils over. S0 and residual sulphuryl chlorideare collected in a cooling trap.

The following is established by gas chromatography.

The residue contains 26.4 g of starting compound.

The degree of reaction is 87.4 percent.

100 g (78% of the introduced quantity) of sulphuryl chloride arerecovered.

The yield of m-dichlorobenzene amounts to 99 percent of the theoretical,based on reacted starting compound.

EXAMPLE 22 The procedure according to Example 21 is followed, but 98 g(0.75 mol) of thionyl chloride are introduced dropwise within 6 hours,instead of sulphuryl chloride.

Conversion: 43.7% after 6 hours.

Yield: 85% of the theoretical of m-dichlorobenzene, based on reactedstarting compound.

EXAMPLE 23 EXAMPLE 24 An equimolar mixture of m-chlorobenzene sulphonylchloride and sulphuryl chloride is introduced dropwise at 30 ml/hourthrough a heated quartz tube (length 50 cm, diameter 1.5 cm) which ischarged with quartz beads (diameter 4 mm).

Reaction Conversion Yield of temperature 71 m-dichlorobcnzene EXAMPLE 25212 g (1 mol) of m-chlorobenzene sulphonyl chlo- C, a solution of 7 g ofazo-bis'isobutyronitrile in g (1 mol) of sulphuryl chloride isintroduced dropwise within 5 hours. Stirring takes place for a further2% hours until completion of the evolution of gas at 80C.

Conversion: 97.3% -Yie1d: 93% of the theoretical of m-dichlorobenzene.

EXAMPLE 26 175 g (1.3 mols) of sulphuryl chloride are added at 180 to200C and for 3 /2 hours to the crude product of Example 5, withoutintermediate isolation of mchlorobenzene sulphonyl chloride. Using acolumn, a1- together ml of distillate are continuously drawn off at ahead temperature of -77 to 122C. The main component is sulphurylchloride. The residue contains 93 g of m-dichlorobenzene.

The yield, based on introduction benzene sulphonyl chloride, amounts to63% of the theoretical.

EXAMPLE 27 g (1.3 mols) of sulphuryl chloride are added to the crudeproduct of Example 6, without intermediate isolation fromm-chlorobenzene sulphonyl chloride, at 1 10 to 120C and withsimultaneous irradiation with a mercury immersion lamp, over a period of3 hours.

Excess sulphuryl chloride is distilled off through a 60 cm silver column(diameter 2.5 cm, filler bodies, glass Raschig rings 4 X 4 mm).

The residue (191 g) contains 27.1 percent of mdichlorobenzene, 3 percentof benzene sulphonyl chloride and 33.0 percent of m-chlorobenzenesulphonyl chloride.

Calculated yield: 53 percent of the theoretical of mdichlorobenzene,based on introduced or reacted benzene sulphonyl chloride andm-chlorobenzene sulphonyl chloride.

EXAMPLE 28 353 g (2 mols) of benzene sulphonyl chloride and 10 g of ironfilings are initially provided, saturated at room temperature withhydrogen chloride gas and, at 48 to 57C, chlorine is introduced untilthere is an increase in weight of 74 g. The product is filtered off withsuction from the catalyst. After adding 400 ml of CCl,, the product iswashed until neutral with 4 X 100 m1 of water. It is dried over Na- SOfiltered with suction, stirred twice with on each occasion 5 g of A1 0and 10 g of bleaching earth, and suction-filtered each time. CCL, isdistilled off at 100 mm.Hg. 175 g (1.3 mols) of sulphuryl chloride areadded to the residue (291 g) at 204 to 21 1C over a period of 2 hours.Simultaneously, through a 40 cm silver-jacketed column (diameter 2.5 cm,Raschig rings 4 X 4 mm), 214 g of distillate are withdrawn at a headtemperature up to 138C.

The residue contains 3 g of benzene sulphonyl chloride, 21 g ofm-dichlorobenzene and 51 g of mchlorobenzene sulphonyl chloride. 85.7 gof mdichlorobenzene are obtained by fractional distillation from thedistillate.

Total yield: 106.7 g of m-dichlorobenzene (0.73 mol), corresponding to42 percent of the theoretical, based on reacted benzene sulphonylchloride or mchlorobenzene sulphonyl chloride, respectively.

3. Process of claim 1 wherein the m-chlorobenzene sulphonyl chloride isreacted in the presence of a halo genation agent to formm-dichlorobenzene.

4. Process of claim 1 wherein the reaction of mchlorobenzene sulphonylchloride to form mdichlorobenzene is carried out in the liquid phase at20 to 300C.

5. Process of claim 1 wherein the reaction of mchlorobenzene sulphonylchloride to form mdichlorobenzene is carried out in the gaseous phase at200 to 400C.

6. Process of claim 1 wherein the m-chlorobenzene sulphonyl chloride isreacted by chlorolysis with sulphuryl chloride or chlorine at 20 to 260Cfor form mdichlorobenzene.

7. Process of claim 1 wherein m-chlorobenzene sulphonyl chloride isreacted in the presence of ultraviolet irradiation or with the additionof a radical former to form m-dichlorobenzene.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3 97321 DATED July 29, 1975 INVE'NT0R(S) Heinz-Ulrich Blank; KarlfriedWedemeyer and I,Thea Ebersber erlhscmmmdmmenmammmsmtemmw-mmnflwpmwtwdmmsmdLdwmPmmt are hereby correctedas shown below:

Page 1, second inventor should read Karlfried Wedemeyer Page 1,Abstract, line 4, the range in temperature should read -20 to 180CColumn 9, line 15, the range in temperature should read -20 to 180CSigned and Scaled this ISEAL] ninth Day Of December1975 A ttest:

RUTH C. MASON C. MARSHALL DANN Attestmg Officer Commissioner ofPatenlsand Trademarks

1. A PROCESS FOR PREPARING M-CHLOROBENZENE SULPHYONYL CHLORIDE ANDM-DICHLOROBENZEE WHICH COMPRISES REACTING BENZENE SULPHONYCHLORIDE WITHCHLORINE IN THE PRESENCE OF A FRIEDEL-CRAFTS CATALYST AS A TEMPERATUREOF FROM 20* TO 180*C, AND AFTER REMOVING SAID CATALYST, REACTINGTHERESULTING MCHLOROBENZENE SULPHONYL CHLORIDE, TO FORMM-DICHLOROBENZENE.
 2. Process of claim 1 wherein the m-chlorobenzenesulphonyl chloride is isolated prior to conversion to m-dichlorobenzene.3. Process of claim 1 wherein the m-chlorobenzene sulphonyl chloride isreacted in the presence of a halogenation agent to formm-dichlorobenzene.
 4. Process of claim 1 wherein the reaction ofm-chlorobenzene sulphonyl chloride to form m-dichlorobenzene is carriedout in the liquid phase at 20* to 300*C.
 5. Process of claim 1 whereinthe reaction of m-chlorobenzene sulphonyl chloride to formm-dichlorobenzene is carried out in the gaseous phase at 200* to 400*C.6. Process of claim 1 wherein the m-chlorobenzene sulphonyl chloride isreacted by chlorolysis with sulphuryl chloride or chlorine at 20* to260*C for form m-dichlorobenzene.
 7. Process of claim 1 whereinm-chlorobenzene sulphonyl chloride is reacted in the presence ofultraviolet irradiation or with the addition of a radical former to formm-dichlorobenzene.